Heat Wave to Break Before Memorial Day Weekend

Local residents face one more day of dangerously hot conditions Wednesday before a cooling trend brings relief in time for the Memorial Day weekend, National Weather Service forecasters said.

Temperatures will peak Wednesday with highs reaching into the 90s across valleys and inland areas, with some locations potentially hitting 100 to 101 degrees. These temperatures range 12 to 18 degrees above normal for late May.

Pasadena is expected to top out at 93.

“Today will be the hottest day of the next 7,” NWS forecasters said in their morning bulletin. “The rising heights, weak gradients and late May sun angles will all combine to bring 3 to 6 locally 8 degrees of warming to most of the areas.”

Heat advisories remain in effect through Thursday evening for most areas away from the beaches as overnight lows will offer little relief from daytime heat.

A weather trough moving across California Friday will begin a substantial cooling pattern, with temperatures dropping 3 to 8 degrees. The cooling will accelerate into Saturday, when most coastal and valley areas will see temperatures a few degrees below normal.

“Big cooling slated for Saturday with lower heights, a deep marine layer and strong onshore flow,” the weather service said.

The holiday weekend forecast calls for morning low clouds along the coast with afternoon clearing. Sunday will see a slight temperature increase of 1 to 2 degrees, with gusty afternoon winds continuing in mountain and desert areas.

Fire weather concerns remain elevated midweek due to the combination of hot conditions and locally gusty winds, particularly in grassy areas that have already dried out, according to the NWS.

Memorial Day itself should see typical May weather with morning low clouds and “near-normal” temperatures.

Here is the latest forecast for Pasadena from the National Weather Service as of 3:47 a.m. on Wednesday, May 21:

Today: Sunny, with a high near 93. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.

Tonight: Clear, with a low around 64. Southwest wind 5 to 10 mph becoming light and variable in the evening.

Thursday: Sunny, with a high near 90. Light and variable wind becoming southwest 5 to 10 mph in the morning.

Thursday Night: Mostly clear, with a low around 63. Southwest wind 5 to 10 mph becoming southeast after midnight.

Friday: Sunny, with a high near 84. East southeast wind 5 to 10 mph becoming south southwest in the morning.

Friday Night: Mostly clear, with a low around 57.

Saturday: Sunny, with a high near 78.

Saturday Night: Mostly clear, with a low around 56.

Sunday: Sunny, with a high near 82.

Sunday Night: Patchy fog after 11:00 p.m. Otherwise, mostly cloudy, with a low around 58.

Memorial Day: Patchy fog. Otherwise, partly sunny, with a high near 81.

Monday Night: Mostly clear, with a low around 57.

Tuesday: Sunny, with a high near 80.